What do the Met police have in common with NASA? They both use engines powered by hydrogen.

For decades, NASA has relied upon hydrogen gas as rocket fuel to deliver crew and cargo to space. Hydrogen is also now being used to power a fleet of Toyota Mirai vehicles used by the Metropolitan Police.

The technology is still relatively new but the National Physical Laboratory (NPL) in Teddington has one of the few hydrogen refuelling stations in the UK.

Cutting edge research

NPL already carries out cutting edge research in hydrogen, fuel cell and electrolyser technologies. So it has been a natural progression for NPL to host one of the first refuelling stations in the UK.

Hydrogen has the potential to be more environmentally friendly than traditional petrol engines in cars.

Good for the environment 

To create power, cars normally burn fuel producing carbon dioxide and other pollutants. In contrast, hydrogen fuel cells produce only one harmless byproduct – water.

Inside the fuel cell, hydrogen (from a tank) and oxygen (from the air) are flowed on either side of a plastic membrane. Parts of the hydrogen atoms (protons) travel through the membrane to the other side, where they fuse with the oxygen to form water.

However, the other parts of the hydrogen atom (electrons) can’t get through the membrane. They take ‘the long way round’ via an electric circuit creating a flow of current. Stacks of fuel cells create enough power to run a car.

The hydrogen at the station is generated via electrolysis on site using mains water and electricity and then dispensed to vehicles from large storage tanks. The electrolyser is capable of generating enough hydrogen to refuel 16 cars each day and refuelling takes only a few minutes.

The refuelling station is open to members of the public who own or lease a fuel cell powered vehicle. And while it would cost an eye-watering £66,000 to buy a Toyota Mirai, you can still take a ride in one courtesy of Green Tomato cabs.

Questions you can ask

Hydrogen fuel cells may seem a complicated concept to discuss with children. But there are questions you can ask – particularly with older children.

What is an atom? What causes global warming? What else can we find hydrogen in? And if you have kids who really like to get hands on, there are some simple experiments that anyone can do.

Make hydrogen foam:
http://www.scienceforkids club.com/hydrogen.html

Make hydrogen gas:

NPL does lots of outreach work, so why not get in touch if you would like them to come in to your school. Of course you could always call a hydrogen-fuelled cab and take a trip to the refuelling station for yourself.

For more information go to www.npl.co.uk/hydrogen